Re-land: ui: Add GLImage unit test framework.

ui/gl/test/gl_image_test_template.h

Index: ui/gl/test/gl_image_test_template.h
diff --git a/ui/gl/test/gl_image_test_template.h b/ui/gl/test/gl_image_test_template.h
new file mode 100644
index 0000000000000000000000000000000000000000..8533ce20c44d7c824e4e1fdf3e52d5935ae57406
--- /dev/null
+++ b/ui/gl/test/gl_image_test_template.h
@@ -0,0 +1,182 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file defines tests that implementations of GLImage should pass in order
+// to be conformant.
+
+#ifndef UI_GL_TEST_GL_IMAGE_TEST_TEMPLATE_H_
+#define UI_GL_TEST_GL_IMAGE_TEST_TEMPLATE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/stringize_macros.h"
+#include "base/strings/stringprintf.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/buffer_format_util.h"
+#include "ui/gfx/buffer_types.h"
+#include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_context.h"
+#include "ui/gl/gl_image.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_surface.h"
+#include "ui/gl/test/gl_image_test_support.h"
+#include "ui/gl/test/gl_test_helper.h"
+
+namespace gfx {
+
+template <typename GLImageTestDelegate>
+class GLImageTest : public testing::Test {
+ protected:
+  // Overridden from testing::Test:
+  void SetUp() override {
+    GLImageTestSupport::InitializeGL();
+    surface_ = GLSurface::CreateOffscreenGLSurface(Size());
+    context_ = GLContext::CreateGLContext(nullptr, surface_.get(),
+                                          PreferIntegratedGpu);
+    context_->MakeCurrent(surface_.get());
+  }
+  void TearDown() override {
+    context_->ReleaseCurrent(surface_.get());
+    context_ = nullptr;
+    surface_ = nullptr;
+    GLImageTestSupport::CleanupGL();
+  }
+
+ protected:
+  scoped_refptr<GLSurface> surface_;
+  scoped_refptr<GLContext> context_;
+  GLImageTestDelegate delegate_;
+};
+
+TYPED_TEST_CASE_P(GLImageTest);
+
+// Copy image to texture. Support is optional. Texels should be updated if
+// supported, and left unchanged if not.
+TYPED_TEST_P(GLImageTest, CopyTexSubImage) {
+  const Size image_size(256, 256);
+  const uint8_t image_color[] = {0, 0xff, 0, 0xff};
+  const uint8_t texture_color[] = {0, 0, 0xff, 0xff};
+
+  GLuint framebuffer =
+      GLTestHelper::SetupFramebuffer(image_size.width(), image_size.height());
+  ASSERT_TRUE(framebuffer);
+  glBindFramebufferEXT(GL_FRAMEBUFFER, framebuffer);
+  glViewport(0, 0, image_size.width(), image_size.height());
+
+  // Create a solid color green image of preferred format. This must succeed
+  // in order for a GLImage to be conformant.
+  scoped_refptr<GLImage> image = this->delegate_.CreateSolidColorImage(
+      image_size, GLImageTestSupport::GetPreferredInternalFormat(),
+      GLImageTestSupport::GetPreferredBufferFormat(), image_color);
+  ASSERT_TRUE(image);
+
+  // Create a solid color blue texture of the same size as |image|.
+  GLuint texture = GLTestHelper::CreateTexture(GL_TEXTURE_2D);
+  scoped_ptr<uint8_t[]> pixels(new uint8_t[BufferSizeForBufferFormat(
+      image_size, GLImageTestSupport::GetPreferredBufferFormat())]);
+  GLImageTestSupport::SetBufferDataToColor(
+      image_size.width(), image_size.height(),
+      static_cast<int>(RowSizeForBufferFormat(
+          image_size.width(), GLImageTestSupport::GetPreferredBufferFormat(),
+          0)),
+      GLImageTestSupport::GetPreferredBufferFormat(), texture_color,
+      pixels.get());
+  // Note: This test assume that |image| can be used with GL_TEXTURE_2D but
+  // that might not be the case for some GLImage implementations.
+  glBindTexture(GL_TEXTURE_2D, texture);
+  glTexImage2D(GL_TEXTURE_2D, 0,
+               GLImageTestSupport::GetPreferredInternalFormat(),
+               image_size.width(), image_size.height(), 0,
+               GLImageTestSupport::GetPreferredInternalFormat(),
+               GL_UNSIGNED_BYTE, pixels.get());
+
+  // Attempt to copy |image| to |texture|.
+  // Returns true on success, false on failure.
+  bool rv = image->CopyTexSubImage(GL_TEXTURE_2D, Point(), Rect(image_size));
+
+  // clang-format off
+  const char kVertexShader[] = STRINGIZE(
+    attribute vec2 a_position;
+    attribute vec2 a_texCoord;
+    varying vec2 v_texCoord;
+    void main() {
+      gl_Position = vec4(a_position.x, a_position.y, 0.0, 1.0);
+      v_texCoord = a_texCoord;
+    }
+  );
+  const char kFragmentShader[] = STRINGIZE(
+    uniform sampler2D a_texture;
+    varying vec2 v_texCoord;
+    void main() {
+      gl_FragColor = texture2D(a_texture, v_texCoord);
+    }
+  );
+  const char kShaderFloatPrecision[] = STRINGIZE(
+    precision mediump float;
+  );
+  // clang-format on
+
+  GLuint vertex_shader =
+      GLTestHelper::LoadShader(GL_VERTEX_SHADER, kVertexShader);
+  bool is_gles = GetGLImplementation() == kGLImplementationEGLGLES2;
+  GLuint fragment_shader = GLTestHelper::LoadShader(
+      GL_FRAGMENT_SHADER,
+      base::StringPrintf("%s%s", is_gles ? kShaderFloatPrecision : "",
+                         kFragmentShader)
+          .c_str());
+  GLuint program = GLTestHelper::SetupProgram(vertex_shader, fragment_shader);
+  EXPECT_NE(program, 0u);
+  glUseProgram(program);
+
+  GLint sampler_location = glGetUniformLocation(program, "a_texture");
+  ASSERT_NE(sampler_location, -1);
+  glUniform1i(sampler_location, 0);
+
+  // clang-format off
+  static GLfloat vertices[] = {
+    -1.f, -1.f, 0.f, 0.f,
+     1.f, -1.f, 1.f, 0.f,
+    -1.f,  1.f, 0.f, 1.f,
+     1.f,  1.f, 1.f, 1.f
+  };
+  // clang-format on
+
+  GLuint vertex_buffer;
+  glGenBuffersARB(1, &vertex_buffer);
+  glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+  GLint position_location = glGetAttribLocation(program, "a_position");
+  ASSERT_NE(position_location, -1);
+  glEnableVertexAttribArray(position_location);
+  glVertexAttribPointer(position_location, 2, GL_FLOAT, GL_FALSE,
+                        sizeof(GLfloat) * 4, 0);
+  GLint tex_coord_location = glGetAttribLocation(program, "a_texCoord");
+  EXPECT_NE(tex_coord_location, -1);
+  glEnableVertexAttribArray(tex_coord_location);
+  glVertexAttribPointer(tex_coord_location, 2, GL_FLOAT, GL_FALSE,
+                        sizeof(GLfloat) * 4,
+                        reinterpret_cast<void*>(sizeof(GLfloat) * 2));
+
+  // Draw |texture| to viewport and read back pixels to check expectations.
+  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+  GLTestHelper::CheckPixels(0, 0, image_size.width(), image_size.height(),
+                            rv ? image_color : texture_color);
+
+  // Clean up.
+  glDeleteProgram(program);
+  glDeleteShader(vertex_shader);
+  glDeleteShader(fragment_shader);
+  glDeleteBuffersARB(1, &vertex_buffer);
+  glDeleteTextures(1, &texture);
+  glDeleteFramebuffersEXT(1, &framebuffer);
+  image->Destroy(true);
+}
+
+// The GLImageTest test case verifies behaviour that is expected from a
+// GLImage in order to be conformant.
+REGISTER_TYPED_TEST_CASE_P(GLImageTest, CopyTexSubImage);
+
+}  // namespace gfx
+
+#endif  // UI_GL_TEST_GL_IMAGE_TEST_TEMPLATE_H_